The present invention relates generally to the trailer towing field, and more particularly, to an improved fifth wheel hitch with an improved locking mechanism that is adjustable to conveniently allow enhanced maneuverability in limited or tight operating areas when required.
Fifth wheel hitches for towing a trailer behind a vehicle have long been known in the art. Examples of state of the art fifth wheel hitches include those presently manufactured by Reese Products, Inc. of Elkhart, Ind. under U.S. Pat. No. 5,707,070 and U.S. patent application Ser. No. 60/313,299 filed Aug. 17, 2001.
These state of the art fifth wheel hitches include a support frame having base rails that are secured to the frame or other structure of a towing vehicle and a pair of spaced guide rails that bridge between the base rails. These fifth wheel hitches also include a head assembly having a jaw assembly for engaging a king pin of a trailer. A head support and a pair of uprights mount the head assembly for relative fore-and-aft sliding movement along the guide rails between a towing position and a maneuvering position. In one embodiment load bearing shoes formed from nylon, polytetrafluoroethylene or other known low friction material are provided in each upright to slide over the surface of the guide rails and allow smooth movement of the head assembly. In another embodiment, a roller arrangement is provided in each upright to roll on the surfaces of the guide rails and allow smooth movement of the head assembly between towing and maneuvering positions. In either of these embodiments, a releasable locking mechanism secures the head assembly in either of the selected positions.
While such state of the art fifth wheel hitches provide excellent overall performance and dependable operation, it is believed that further design improvements are still possible. The present invention relates to an improvement in the locking mechanism that provides for smoother overall operation and enhanced customer satisfaction.
In accordance with the purposes of the present invention as described herein, an improved adjustable fifth wheel hitch is provided for towing a trailer behind a motor vehicle. The adjustable fifth wheel hitch includes a support frame having a pair of spaced guide rails. At least one of those guide rails has first and second apertures therein. The adjustable fifth wheel hitch also includes a head assembly having a jaw assembly for engaging a trailer and means for mounting the head assembly on the pair of spaced guide rails so that the head assembly is selectively displaceable between a towing position and a maneuvering position.
A lock is provided on the head assembly. The lock includes at least one bar latch, a biasing element and a cam engaging the biasing element. The bar latch is selectively received and held in the first aperture in the guide rail to releaseably lock the head assembly in the towing position and in the second aperture in the guide rail to releaseably lock the head assembly in the maneuvering position.
More specifically describing the invention, the means for mounting the head assembly on the pair of spaced guide rails may comprise, for example, low friction shoes, rollers or any other appropriate structures which allow for smooth sliding movement of the head assembly over the guide rails of the support frame. Still further describing the invention, the lock of the head assembly includes a first bar latch, a second bar latch, the biasing element, and the cam for engaging the biasing element. Each of the bar latches is substantially L-shaped in one possible embodiment. The biasing element may comprise a leaf spring and the cam may comprise a roller that engages and rolls over a surface of that leaf spring.
In accordance with still another aspect of the present invention, the first and second cooperating apertures in the guide rail may be offset from one another with respect to a longitudinal axis of the guide rail. Similarly, the first and second bar latches are offset in the same manner. Accordingly, the first bar latch only aligns with the first aperture and therefore can only be received in the first aperture, not the second aperture. Likewise, the second bar latch aligns only with the second aperture and, therefore, can only be received in the second aperture, not the first aperture.